The second row seats of many vehicles typically are bench seats that include an armrest that pivots freely in the center occupant location. The armrest is in its down position when there is no occupant seated in the center location.
Because the armrest is freely pivotable, there is ordinarily no locking mechanism provided to hold it in one position or the other. However, under any one of a variety of circumstances, it may be preferred to have the armrest locked in its upright or stowed position.
One of the reasons locks are not generally provided to hold the armrest in place is that typically locks and latches require an operator to move an actuator in both the locking and unlocking directions along with a third motion to hold in place the lock itself just to make sure the lock does not work its way open.
Accordingly, a system of locking a pivoting armrest into its upright position remains desirable yet wanting.